1. Field
Embodiments of the present disclosure relate to a dish washing machine having a structure allowing wash water to be evenly sprayed into a washing tub.
2. Description of the Related Art
A dish washing machine, which generally washes dishes by spraying high-pressure wash water onto dishes, usually performs operations of preliminary washing, main washing, rinsing, and drying. In the preliminary washing, wash water having no detergent introduced into the dish washing machine is sprayed to remove debris from the dishes. In main washing, the dishes are cleaned with detergent introduced into the sprayed wash water from a detergent feeder.
The dish washing machine generally includes a cabinet provided with a washing tub, a pump to generate wash water pressure, a dish basket adapted to retain dishes and installed in the washing tub to be movable forward and backward, and spray units to spray wash water onto the dish basket, and a connection flow passage to connect the pump to the spray unit, and a flow passage switching valve to selectively move the wash water from the pump to multiple spray units. The dishes are washed by the wash water sprayed from the spray unit.
The dish basket includes an upper dish basket arranged at an upper portion of the washing tub, and a lower dish basket arranged at a lower portion of the washing tub.
Conventionally, spray units are positioned at the upper and lower sides of the upper dish basket and at the upper side of the lower dish basket. In the case that the spray units are rotatably arranged, there may be dead zones at the corners of the rectangular washing tub which the sprayed wash water does not reach.
A spray unit having a structure causing the spray unit to rotate with a variable length has been proposed to eliminate dead zones which the wash water does not reach. This structure, which rotates the spray unit through reaction of the spray water pressure may eliminate the dead zones, but it may not achieve the effect of divided or intensive washing only for a specific region.
In addition, there has been proposed a connection structure to connect a spray unit, a drive unit to linearly drive the spray unit, and a flow passage connecting the spray unit and a pump to each other using a link or a flexible hose. However, this structure may produce great loss of pressure in the flow passage, and durability of the flow passage may be low.
In addition, in the case that the spray unit is fixed to the dish basket, the flow passage may be inefficiently disposed, thereby resulting in great loss of pressure in the flow passage and a complex structure of the dish basket.